IMAGE  EVALUATION 
lEST  TARGET  (MT-3) 


1.0 


I.I 


1.25 


M 

122 

M 

1.8 


U    111.6 


Photographic 

Sciences 
Corporation 


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WEBSTER,  N.Y.  14580 

(716)  872-4503 


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CIHM/ICMH 

Microfiche 

Series. 


CIHM/ICMH 
Ccllection  de 
microfiches. 


Canadian  institute  for  Historical  Microreproductions  /  Institut  Canadian  de  microreproductions  historiques 


1 


Technical  and  Bibliographic  Notes/Notes  techniques  et  bibliographiques 


The  Institute  has  attempted  to  obtain  the  best 
originsi  copy  available  for  filming.  Features  of  this 
copy  which  may  be  bibliographically  unique, 
which  may  alter  any  of  the  images  in  the 
reproduction,  or  which  may  significantly  change 
the  usual  method  of  filming,  are  checked  below. 


D 


D 


D 


0 


y 


D 


Coloured  covers/ 
Couverture  de  couleur 


I     I    Covers  damaged/ 


Couverture  endommagAe 

Covers  restored  and/or  laminated/ 
Couverture  restaur6e  et/ou  peiliculAe 


□    Cover  title  missing/ 
Le  titrs 


D 


de  couverture  manque 


I      I    Coloured  maps/ 


Cartes  g6ographiques  en  couleur 

Coloured  ink  (i.e.  other  than  blue  or  black)/ 
Encre  de  couleur  (i.e.  autre  que  bleue  ou  noire) 


|~~|    Coloured  plates  and/or  illustrations/ 


Planches  et/ou  illustrations  en  couleur 


Bound  with  other  material/ 
Relii  avec  d'autres  documents 


Tight  binding  may  cause  shadows  or  distortion 
along  interior  margin/ 

La  reliure  serr6e  peut  causer  de  I'ombre  ou  de  la 
distortion  le  long  de  la  marge  intArieure 

Blank  leaves  added  during  restoration  may 
appear  within  the  text.  Whenever  possible,  these 
have  been  omitted  from  filming/ 
II  se  peut  que  certaines  pages  blanches  aJoutAes 
lori  d'une  restauration  apparaissent  dans  le  texte, 
mals,  lorsque  cela  6tait  possible,  ces  pages  n'ont 
pas  At6  filmAes. 


Additional  comments:/ 
Commentaires  supplAmentalres; 


L'Institut  a  microfilm^  le  meilleur  exemplaire 
qu'il  lui  a  6tA  possible  de  se  procurer.  Les  details 
de  cet  exemplaire  qui  sont  peut-Atre  uniques  du 
point  de  vue  bibliogrnphique,  qui  peuvent  modifier 
une  image  reprodulte,  ou  qui  peuvent  exiger  une 
modification  dans  la  methods  norrnale  de  filmage 
sont  indiqu4s  ci-dessous. 


r^'l   Coloured  pages/ 


D 


Pages  de  couleur 

Pages  damaged/ 
Pages  endommagies 

Pages  restored  and/oi 

Pages  restaur6es  et/ou  pellicul6es 

Pages  discoloured,  stained  or  foxei 
Pages  d6coior6es,  tachet^es  ou  piqu6es 

Pages  detached/ 
Pages  ditachdes 

Showthrough/ 
Transparence 

Quality  of  prir 

Quality  inigale  de  I'impression 

Includes  supplementary  materit 
Comprend  du  matirie!  supplAmentaire 

Only  edition  available/ 
Seuie  Mition  disponibie 


I — I  Pages  damaged/ 

I — I  Pages  restored  and/or  laminated/ 

I — I  Pages  discoloured,  stained  or  foxed/ 

I      I  Pages  detached/ 

r~~|  Showthrough/ 

I      I  Quality  of  print  varies/ 

I      I  Includes  supplementary  material/ 

I — I  Only  edition  available/ 


Pages  wholly  or  partially  obscured  by  errata 
slips,  tissues,  etc.,  have  been  refilmed  to 
ensure  the  best  possible  image/ 
Les  pages  totalement  ou  partiellement 
obscurcies  par  un  feuillet  d'errata,  une  pelure, 
etc.,  ont  M  film6es  A  nouveau  de  fa^on  A 
obtenir  la  meilleure  image  possible. 


Th 
to 


Th 
po 
of 
fill 


Or 
be 
th 
sic 
ot 
fir 
9k 
or 


Th 
shi 
Til 
wt 

Ml 
dif 
en' 
bei 
rig 
reci 
ma 


This  item  is  filmed  at  the  reduction  ratio  checked  below/ 


Ce  do 
10X 

icum 

ant  est  fil 

m6  au  taux  de 
14X 

rAdu 

ction 
18X 

indii 

^ut  c 

i-dei 

sous 
22X 

26X 

30X 

1 

jZ 

^^ 

1 

12X 

16X 

20X 

24X 

28X 

32X 

1 

ails 

du 

idifier 

une 

nage 


The  copy  filmad  hare  has  boan  raproducad  thanks 
to  tha  ganarosity  of: 

University  of  British  Columbia  Library 


Tha  imagas  appaaring  hara  ara  tha  bast  quality 
possibia  considaring  tha  condition  and  legibility 
of  the  original  copy  and  in  Iceeping  with  the 
filming  contract  specifications. 


Original  copies  in  printed  paper  covers  ara  filmed 
beginning  with  the  front  cover  and  ending  on 
the  last  page  with  a  printed  or  illustrated  impres- 
sion, or  the  bacic  cover  when  appropriate.  All 
other  original  copies  are  filmed  beginning  on  the 
first  page  with  a  printed  or  illustrated  impres- 
sion, and  ending  on  the  last  page  with  a  printed 
or  illustrated  impression. 


The  last  recorded  frame  on  each  microfiche 
shall  contain  the  symbol  -^  (meaning  "CON- 
TINUED"), or  the  symbol  V  (meaning  "END"), 
whichever  applies. 

IVIaps,  plates,  charts,  etc.,  may  be  filmed  at 
different  reduction  rados.  Those  too  large  to  be 
entirely  included  in  one  exposure  are  filmed 
beginning  in  the  upper  left  hand  corner,  left  to 
right  and  top  to  bottom,  as  many  frames  as 
required.  The  following  diagrams  illustrate  the 
method  : 


L'exemplaire  filmd  fut  reproduit  grAce  A  la 
gAnArositA  da: 

University  of  British  Columbia  Library 


Les  images  suivantes  ont  6x6  reproduites  avac  le 
plus  grand  soin.  compta  tenu  de  la  condition  et 
de  la  nettetA  de  i'exempiaire  film*,  et  en 
conformity  avec  les  conditions  du  contrat  de 
filmage. 

Les  exemplaires  originaux  dont  ia  couverture  en 
papier  est  lmprim<ie  sont  filmAs  en  commen^ant 
par  le  premier  plat  et  en  terminant  soit  par  la 
derniAre  page  qui  comporte  une  empreinte 
d'impression  ou  d'lilustration.  soit  par  le  second 
plat,  salon  le  cas.  Tous  les  autres  exemplaires 
originaux  sont  filmis  en  commenpant  par  la 
premiere  page  qui  comporte  une  empreinte 
d'impression  ou  d'illustratlon  et  en  terminant  par 
la  derniilire  page  qui  comporte  une  telle 
empreinta. 

Un  des  symboles  suivants  apparaftra  sur  la 
derni^re  image  de  cheque  microfiche,  selon  le 
cas:  le  symbole  — ^  signifie  "A  SUIVRE",  le 
symbole  V  signifie  "FIN". 

Les  cartes,  planches,  tableaux,  etc.,  peuvent  dtre 
fiim^s  A  des  taux  de  reduction  diffdrents. 
Lorsque  le  document  est  trop  grand  pour  dtre 
reproduit  en  un  seul  cliche,  il  est  film*  d  partir 
de  Tangle  sup^rieur  gauche,  de  gauche  d  droite, 
et  de  haut  en  bas,  en  prenant  le  nombre 
d'imagas  ndcessaire.  Les  diagrammes  suivants 
illustrent  la  m*thode. 


rata 


elure. 


3 


I2X 


1 

2 

3 

1 

2 

3 

4 

5 

6 

1 

E 
t 

ii 
o 


i>! 

as 

CO 


tei 


tioii 
311- 


I 

1 


«v  H.  s.  JKNNJNGs 

tbM. »  full  k,„„vto,l  Jif  ", ,  ''  "'^'":'"««  ""'I  «.«  law,  „.„ '1  !;"'"",,'""•  """  "  «'"1v 
an  n...ler,U„ui„,  „"n:;.  ,  ^  -  ^,^"  -e  of  „„e  Pm:™',  ^^1,  ';:;.■;  .''I  '""  ""i* 
to  those  of  hi,ri,er  aniii..,?«     rl,       "^  "^''^''"  "lembers  oC  tho  »..     ^      '"""sli  .1  key  t« 

Want,  the  other  broadTuVp  X  1^""'""''«1'-'  -''^"ai    w  ^  J;:??" "'  ""'  '"'"^^ 

a'oiigone  side  of  the  bo.lv   n  m  ""'"  ^'''^  '»'»"t  «"<1   i  J,  "'  "'"■•"«'  '"'<! 

which  the  ,uoutluuL"„      r  "^  ""^'"«'«'»'I'-"gthe,c     .  H  ''  ''"'•'^^•^  ^'l>"<iudv 

«iUe  (on  Which  tl     c  r:in  '!  """,  ''^  •''■•^^'•''«»^f.''      J    .^'^r""/-    '^''-  -'«  on 

tl^e  u„i„,al  iscovored  uSl  «    !  ?'"""  '''^^  "'^  '''«  '"'oral  s  ,'    't.  '"''  *'"'  ''"'>'-'-t« 

'»  the  direction  of  thrnlv  I'  'T;""'"''^"'«'"<^I'  it  n,ove       a.  ,-,''"  ""^"'^  ■^"'•'a-'e  "f 

other  the  posterior  e^^/"'"^"'^'' ''''"•^«'- «'''^  that  nu/,:;!;,'^ 

,       I"  what  u,ight  I  e  oalJe,!  H     •  '  ^""''■'■"'"  ^"'^^  *''« 

•'"•-•kward,  so  that  the  a2  !  ,         ""™'''  '^"'"'•"on  of  ail-u.s   .,,    . 

'^-'«.    Now,  When  a  cl'    "«  L"'?  '"'"'^'•^''  ^^  the  san  e  t    ,e  it    "'  "''  ''"••'»  ^^^ike 

''«  »>y  it  striking  again  ^^'  '.  T"^"'"''^ '"  ^'"'  ^'"vironnK.nt       /,     n''"^''""^  ""  '^«  ^ong 

tion  of  ptrC„,!V''r'-'«« -"•"  l'a«e.l  on  i„v    r  :^°*    ^''^  '""'y  ^ease  their 

lOiJ 


106 


HULLKTIN   OF    THK    UNITKD    STATES    FISH    COMMISSION. 


movement,  while  those  in  the  oral  fjroove  and  the  gullet  continue  active.  Aa  anon- 
8e(|uence  locomotion  ceanes;  the  animal  comes  to  rest  against  the  solid  body,  while 
the  cilia  of  the  oral  groove  continue  to  drive  a  stream  of  water  to  the  mouth.  This 
reaction  to  a  solid  body  may  be  callet;  thigniotuxis.  If  the  loose  solid  body  is  a  mass 
of  bacterial  zooghea,  the  stream  of  water  carries  iniinbers  of  bacteria  to  the  montli, 
where  they  pass  into  the  internal  iiroto])Iasni  of  the  animal  and  are  digested;  thus 
Paramecium  gets  its  food.  But  the  animal  conducts  itself  in  exactly  the  same  way 
toward  other  loose  tlbrons  bodies,  such  as  bits  of  (;loth,  paper,  sponge,  or  the  liiic,  the 
presence  or  absence  of  material  that  will  serve  aa  food  having  nothing  to  do  with  the 
production  of  the  reaction.  On  the  other  hand,  the  substances  held  in  solution  in 
the  water  have  a  marked  effect  on  the  tendency  of  tiie  Paramecia  to  react  in  the 
manner  above  described.  If  the  water  is  faintly  acid  in  reaction,  the  Paramecia  are 
much  more  inclined  to  come  to  rest  as  just  described.  This  is  especially  noticeable  in 
water  containing  carbon  dioxide.  The  presence  in  the  water  of  an  alkali  in  solution 
has,  on  the  other  hand,  precisely  the  opposite  ettect,  tending  to  inhibit  the  thigmotactic 
reaction. 

2.  Any  other  change  in  the  conditions,  of  such  a  nature  aa  to  act  as  a  stimulus, 
causes  a  definite  change  in  the  nmveinents,  which  is  of  a  stereotyped  character,  being 
of  the  same  nature  for  almost  every  stimulus.  When  stimidated,  Paramecium  swims 
backward,  turns  toward  its  own  aboral  side,  then  swims  forward  again.  The  same  reac- 
tion is  produced  by  stimuli  of  the  most  varied  kinds — by  acids,  alkalis,  and  neutral  salts, 
by  heat,  by  cold,  by  mechanical  shock.  The  reaction  is  the  same  wlietlier  the  stimulus 
first  affects  the  anterior  end,  the  posterior  end,  one  side,  or  the  entire  surface  of  the 
atumal  at  once.  The  direction  in  which  the  animal  swims  has  thus  no  relation  to  the 
localization  of  the  stimulus.  If  the  stimulus  comes  from  the  anterior  tMi«l,  swimming 
backward  of  course  carries  the  animal  away  from  it;  if  the  same  stimulus  comes  from 
the  posterior  end,  swimming  backward  carries  the  animal  toward  it.  If  an  injurious 
chemical  substance  diffuses  in  such  a  way  as  to  first  come  in  contiM;t  with  the  posterior 
end  of  a  resting  Paramecium,  the  latter  therefore  swims  backward  directly  int«>  the 
substance  and  is  killed.  The  turning  is  likewise  without  relation  to  the  positi<m  of 
the  stimulus.  The  animal  always  turns  toward  its  own  aboral  side,  so  that  the 
absolute  direction  ill  which  it  turns  depends  npoii  the  chance  position  of  the  aboral 
side  when  the  turning  begins.  As  the  animal  contiiinally  revolves,  both  when  swim- 
ming forward  and  when  swimming  backward,  it  is  impossible  to  predict  in  which 
direction  the  aboral  side  will  lie  after  the  animal  has  swum  backward  a  distance  from 
its  position  when  stimulation  occiiis;  and  observation  shows  that  when  Paramecium 
strikes  on  one  side  against  an  obstruction,  it  is  fully  as  likely  to  turn  toward  the 
obstrnction,  after  swimming  backward,  as  to  turn  away.  In  the  former  ease  it  of 
course  strikes  the  obstruction  again;  the  whole  reaction  is  then  repeated.  Owing  to 
the  continual  rotation  on  the  long  axis,  the  aboral  side  will  probably  be  in  a  new 
position  next  time,  so  that  the  animal  will  turn  in  a  new  direction,  if  this  repetition 
is  continued,  the  Paramecium  is  certain  finally,  by  the  laws  of  chance,  to  avoid  the 
obstacle. 

The  factors  determining  the  direction  of  motion  in  ParaniiLjcium  are  thus  internal; 
the  direction  of  its  movements  has  no  relation  to  the  position  of  external  objects.  This 
result  is  of  fuiid.imental  significance  for  interpretation  of  the  movements  of  these 
creatures,  and  throws  a  flood  of  light  on  many  of  the  phenomena  of  their  life.  Study 
of  some  other  Infusoria  in  the  light  of  the  result  on  Paramecium  has  shown  that  the 


same 

ward, 

glass  j 

poster 

morphi 

forwan 

of  the 

certain 

He; 

e.vlendt 

into  a  ] 

snbstan 

leave  it 

8"bstan( 

niecliaiii 

attracteti 

edge  of  f 

Ibit  J'an 

that  man 

•t'iict,  but 

produce  t 

o'lfer  tiuh 

*'t^»nmlns  ( 

tl'o  outer 

turns  towi 

scheme  of] 

more;  leac 

boundary  r 

many  Par; 

appear  to  h 

In  case 

shows  that 

«s  produced 

are  prevei)t( 

It  was  i 

the  one  han 

the  Paramec 

that  they  do 

I'>  these  the 

toward  them, 

soon  as  the  P 

"ll  of  these  ti,„ 

Ufnonorelntion 
"'"8  on  t|,„  „t,, 

tlie  locttJizati,,,, 
'interior  end  n«i 
liowever.  tin,  „h, 
NiiniuluH  w.iH  ,1... 
reflexes  of  (ho  J] 


Tin:    PROTOZOA    OF   LAKK   KRIR. 


107 


saiiiti  is  true  for  tliese.  Sinnmtimtutn  (tmlthjuuni  when  stiiiiulatcd  coiitnictH,  Hwinis  h;uk- 
ward,  turns  toward  tlio  aboral  sido,  iind  swims  forward.  U'touclii'd  with  a  spicuh'  of 
glaas  at  its  antorior  ciul  it  swims  backward,  aicay  from  the  glass;  if  touched  at  the 
posterior  end  it  likewise  swims  backward,  therefore  toward  the  glass.  Stciitor  poh/- 
morphun  when  stimnlated  contracts,  swims  backward,  turns  to  the  right,  then  swims 
forward,  the  direction  of  motion  having,  as  in  theother  cases,  no  relation  to  hx^alization 
of  the  stimulus.  Similar  results,  not  yet  jmblished  in  detail,  have  been  obtained  witii 
certain  Flagellata,  as  well  as  with  other  Ciliata.* 

Hesidcs  determining  the  general  mechanism  of  the  reactions  of  raramecium,  an 
extended  study  was  made  of  the  elVects  upon  its  activities  of  ditl'erent  chemicals.  If 
into  a  preparation  of  Paramecia  mounted  Jipoii  the  slide  a  drop  of  some  chemical 
substance  in  solution  is  introduced,  the  Paramecia  may  either  collect  in  the  drop  or 
leave  it  entirely  empty.  In  the  former  case  they  show  i)osi(ive  chemotaxis  to  the 
substance;  in  the  latter  case,  negative  ehen\otaxis.  As  to  what  might  bo  called  the 
mechanism  of  (rhemotaxis,  the  following  was  made  out.  The  Paramecia  are  not 
attracted  by  the  drop  of  substance  into  which  they  gather.  They  may  };raze  the  very 
edge  of  the  drop  without  swerving  a  particle  from  tlieir  course  so  as  to  pass  into  it. 
15ut  I'aramecia  when  lirst  brought  upon  the  slide  swim  ra])i«ny  in  every  direction,  so 
that  many  will  quickly  come  by  chance  against  the  edge  of  such  a  droj).  They  do  not 
react,  but  swim  straight  ahead— the  substance  in  tln^  drop  not  acting  as  a  stimulus  to 
produce  the  motor  reaction  abctve  described.  I»nt  on  i»assing  across  the  drop,  the 
outer  fluid  does,  after  the  Paramecia  have  been  in  tlie  drojiof  the  chemical,  act  as  a 
stimulus  to  jtroduce  the  motor  reaction.  The  Paramecium  therefore,  on  coming  to 
the  outer  edge  of  the  drop,  swims  backward,  thus  returning  into  the  drop.  It  then 
turns  toward  the  aboral  side  and  swims  forward  (in  accordance  with  the  general 
scheme  of  reaction  above  dcscribe'l).  It  thus  comes  to  the  outer  edge  of  the  drop  oiwxt 
more;  reacts  again,  and  this  being  kept  uj),  is  continually  prevented  from  crossing  the 
boundary  of  the  drop  into  the  surrounding  water.  The  same  process  is  repeated  for 
many  Paramecia,  until  in  time  tiie  drop  swarms  with  the  Infusoria,  so  that  they 
appear  to  have  been  attracted  into  if. 

In  case  of  a  substance  in  which  tlie  Paramecia  do  not  collect  at  all,  observation 
shows  that  the  motor  reaction  fswimnung  backward,  turning,  and  swimming  forward) 
is  produced  when  the  Paramecia  come  against  the  drop  from  the  outside;  hence  they 
are  prevented  from  entering  and  the  drop  remains  empty. 

It  was  found  possible  to  classify  chemical  compounds  thus  into  two  classes.  On 
the  one  hand  may  be  placed  together  those  whiih  do  not  produce  the  reaction  when 
the  Paramecia  enter  them,  but  throw  the  animals  into  such  a  physiological  condition 
that  they  do  react  when  they  i)iiss  out  of  a  drop  omtaining  the  substance  in  ([uestion. 
In  these  the  Paramecia,  therefore,  gather  and  are  said  to  be  positively  ehemotactic 
toward  them.  On  the  other  hand  are  substances  which  produce  the  motor  reaction  as 
soon  as  the  Paramecia  come  in  contact  with  them,  so  that  the  aninnds  do  not  enter 


•  Th«  reactions  of  i\  larcu  luiinlHU'  i>t'  I'loto/oii  liii\  e  lu-uii  stnilied  since  tlio  above  wns  written.  In 
all  of  tlieHB  tliu  (lircrtioM  ot  tiiniin;;  \\i\a  loiind  to  Ixt  (leterniincd  entirely  liy  internal  fiietori',  iind  to 
ba\e  no  relation  to  the  po.sition  of  tlio  Nonrce  <if  stiniiihiH.  The  direction  of  motion  ulon;;  the  body 
axis,  on  tli<^  otbor  hand,  was  found  in  a  nunibci'  of  imkch,  for  mechanical  Htiinnli,  to  bo  detcnnincd  by 
the  locali/ation  of  the  HtiinnluH.  I.oxodfn  rontnim,  for  cxaniple,  when  tonched  with  a  h1'''n8  ''od  at  the 
anterior  end  swiniH  backward  ;  touched  at  the  posterior  end  it  swims  forward.  Kor  chemical  Ntimuli, 
however,  the  h/mcmci!  of  any  Nuch  de|ienilonce  of  the  direction  of  movement  on  tliii  localisation  of  the 
HiiuinluM  wa^4  deuioiiRtrated.  For  details,  see  a  ))aper  by  the  author  on  "The  n\ovenients  and  motor 
reflexes  of  lh&  Flagellata  and  (Jiliula,"  in  the  American  .lourual  of  I'bysiolo^y,  January,  I'JOO. 


108 


HlLLI'/riX    nl'    Tlir.    IMIKl)    SI'ATKS    KISII    COMMISSION. 


Hohitioiia  of  tliPHo  (;onii)onii(ls  at  all,  and  may  1k^  said  to  bo  iiefjatively  diemota<;tic 
toward  them. 

In  the  foriinu'  j^roiip  (siil)stun(;e8  toward  which  tho  Piuainocia  show  poHitive  chciii- 
otaxis)  belong  all  acids,  and  salts  whoso  solutions  have  an  acid  reaction  or  contain 
hydrogen  ions,  as  in  salts  of  the  heavy  metals.  In  the  group  of  substances  toward 
which  the  Paramecia  are  negatively  chemotactic  belong  all  alkalies  and  substances 
having  an  alkaline  reaction,  as  well  as  almost  all  compounds  which  contain  ions  of 
the  alkali  and  earth  alkali  metals  in  their  solutions.  Certain  substances  take  an 
int4.>rmediate  place.  Containing  the  ions  of  an  alkali  or  earth  alkali  metal,  they  ^.o- 
<luce  the  motor  reaction  when  the  Paramecia  enter  a  drop  of  tinid  containing  them; 
but  having  likewise  hydrogen  ions,  they  also  cause  the  animals  to  react  when  they  leave 
the  drop.  Kxani|)les  of  such  substances  are  potassium  and  ammonium  bichromate. 
In  these  cases  the  hydrogen  ions  seem  to  be  active  (in  their  characteristic  way)  in  a 
more  dilute  solution,  and,  therefor",  farther  from  the  center  of  a  diffusing  drop  than  are 
the  ions  of  the  metals.  Tiie  I'aramecia,  therefore,  enter  the  outer  margin  of  the  droi» 
and  are  unable  to  lcav<^  it,  while  at  the  same  time  they  are  unable  to  pass  to  the  center 
of  the  drop.    They  thus  gather  in  a  ring  about  the  drop,  leaving  the  center  emi)ty. 

The  cl.assification  of  substances  into  those  toward  whi(!h  the  Paramecia  are 
positively  chemotactic  on  the  one  hand  ai' I  those  toward  M'hich  they  are  negatively 
chemotactic  on  the  other,  thus  follows  the  lines  of  a  chemical  classiflcation;  the 
former  including  acids,  the  latter  alkalies  and  salts  of  the  alkali  and  earth  alkali 
metals. 

I'iXperimentsvtion  showed  that  the  relative  injuriousness  of  solutions  has  compar- 
atively little  to  do  with  the  nature  of  the  chomotaxis.  Paramecia  are  repelled  strongly 
by  many  substances  that  are  scarcely  injurious  at  all,  while  they  enter  without 
hesitation  other  substances  in  which  they  are  at  once  killed.  The  repellent  powers  of 
difl'erent  chemical  compounds  are  in  no  way  proportional  to  their  injurious  effects. 

The  rc»searches  on  chemotaxis  have  thus  far  been  restricted  almost  entirely  to 
Paramecium,  but  the  general  laws  obtained  for  this  animal  promise  to  throw  much 
light  on  related  phenomena  in  others. 

As  described  above,  positive  and  negative  chemotaxis,  or  the  collecting  in  or 
avoidance  of  certain  chemicals,  takes  place  through  the  mechanism  of  the  general 
motor  reaction  first  described.  The  only  activity  of  the  Paramecia  concerned  in  it  all 
is  tlie  swimming  backward,  turning  toward  the  aboral  side,  then  swimming  forward, 
Wiien  stimulated.  The  (|iialitative  differences  that  seem  a)>parent  in  their  reactions 
toward  different  substances  depend  merely  ni)()n  what  does  and  what  does  not  act  as 
a  stimulus. 

The  mechanism  of  c(»lle«;ting  in  or  avoiding  agencies  or  conditions,  other  than 
chemical,  is  exactly  the  sa:ne  as  that  just  described.  In  the  case  of  tenijterature,  for 
example,  certain  grades  of  heat  or  cold  prodn<;o  motor  reaction,  so  tliat  the  Paramecia 
do  nut  enter  these;  or,  if  already  within  a  zone  of  sucli  temperature,  they  continue 
moving  about  violently  till  a  chance  movement  carries  them  into  a  region  where  the 
temperature  is  not  such  as  to  cause  a  reaction;  there  they  remain.  In  general,  there- 
fore, the  I'aramecia  gather  and  remain  in  substances  or  conditions  which  do  not  cause 
the  motor  reaction,  while  they  leave  emi)ty  sucdi  substances  or  (conditions  as  do  cause 
their  one  motor  reaction.  It  follows  that  they  collect  in  regi(tns  of  a  certain  tempera- 
ture, avoiding  great  heat  or  c<»hl,  and  that  they  collect  in  water  holding  in  solution 
substances  of  an  acid  character,  avoiding  alkaline  solutions.     I'nder  natural  c(Hi- 


ditioi 

theiui 

in  del 

togetl 

to  qui 

thePti 

the  P,i 

Tl 

in  the 

course, 

in  the 

amount 

cbangef 

backwa 

random 

reactit)!) 

stimulus 

niaypasf 

carbon  c 

M»  carboi 

Or,  if  it  ( 

to  be  acti 

'■«  by  (;hai 

"loutb  of 

Piiraniecii 

.joined  by 

(c-vcreted 

This  r 

ature,  by  ( 

tciHl  to  pn 

chance  dir 

Thus  1 

leaction  to 

while  undei 

It  is  ob 

out  of  cert! 

I)reserving  ( 

show  no  iui 

'"^aine  niaum 

their  needs. 

conditions  ai 

soon  die.    'i 

similar  anwu 

covering  evei 
of  the  water 

s'i«:ht  change 
though  a  few 
P'ants,  the  pr 


THK    PItOTOZoA    OK 


•'AKK    Kiirj.;. 


109 


rf---=?F~^^^^^^         - 

amounts  of  certain  ,.|.«m!  "^''"''"  *"•  '"«"'■  ttMn.uM.h  .'''■'' "''^'' •'''''''^'e.s 

cbun.es  arc  «/^h^  r S:^?  J^ ''"'  •""  ^'^"  "^--01;:;.::^^       ^  '-« 

backward  a  short  disfa,.  1  !  '^  '''  *'  sf''"<Wus,  the  p. ^'""■'-     ' '  these 

random  one  so  far     ^2'      T  '""'""'^  ""•^'  -^'0  (  n  a  •,•;'*'''"?'. '''^''''"P''''  '^win.s 
reaction  is  reneafedl^r"'  ''^•*"'*^  '"«  c""cerne      a  ."  "'''"'''  ''^  ""  ♦^"tirely 

stimulus.    cS.l  .1'""*'^  "•«  ^•^^«'««-"mro    es':',::;^'';"'''^  """''^•'-    '^^"is 

-aypass  b. chj:;t:';::;-;;;;;on«  cause  no  i::,!;;:.  "^^i  r^j-^ ^--^^•^ "^' 

carbon  dioxide,  which  th«v  j  ^  ^^''  '  ^ra.necia,  where  tli«  JT  ^  '^•■«"'«<-inni 
'">  carbon  dioxide  cle  m  '  ''''''^'''^-  ^"^>  ^  'e  nr  o  n  T"'  ''  '^''"•^^'^  «''*'' 
Or,  if  it  con.es  „  co,  tac  m  '?'"""'  ««  "'«  i^t  an  ec  u  ?  "'^  '''''''  ^""tni-in,. 
to  be  active     tLT  '"'  ''  '^"«'^'  ««ft  body  it  stol  '"'""  ^''*''  ^^e  others 

-  by  cha^:  a  b^  ;rr"^  --^  '^  «trean,  onS^;;^     «  -«'  ciiiacontinnin, 

"'outh  of  the  anhna    sothrH    '""*^^"'"'  ""'^^  «trean.  can- 1  Z        I  '""  '^"  "'^'  '^""d 
I'aramecium  uZrlt?  ^^'^^  '^''^'^  «-^  food.    B,  t       ,     ,       "^  ^"'"^^'''^  '"t"  the 

fined  by  oth^r;^  -  r-^;^;-|e«nitei,  ..i;:::t",r  ^^^^^  '"'-'''  '"« 

•eaction  to  Ite    eoldi;.'  ''"'T''  ''  ^'^^'^'^cly  s  ,np  e    t     v"!    "'''  ''  "  ■^^''°'""«- 
wbiieundero    er   on       ;rT^:""'"^  backwTv  ^t„    X''"^".'^''^  «'-  '"ode  of 

't  is  Obvious  t,::"     e"   ,  ;r  ^:.^'"'^^  '-•«-'>'  -'ea^es""""^^'  '^"•""""•»«'  i-vanl.-_ 

«bow  no  Lli^S'f  i  ;:"^'"'"''''-*«"  -^1  cha  ^"  ;:.;;j^   r^  ^  -'c,uate  ibr 
saM.e  manner,  if  t  ey  r "  -f  f 'ir  "'  ''^'«"  "^"  cboi.l,   ;,X  '  '     '•     "'^  ''"^'""-•'h        " 
"'c»-  needs.    Cha  ce      '    ,  '''^^' "'^^'«  "o  po  v^r^- '^  f,'\^'^^^^^^  the 

conditions  and  ffivin'i    ft,  r  "'''"!/«ctor  i„  brin^in/tVe  P 'i.    "'^: '^'^^'■'' "ct'ons  to 
soon  die.    This  ..,  '  ""*^  '^  the  chances  are  ,J,r      «'a«necnn«  into  nroner 

covering- everything  J7,^,tL>'  """'^'""■^  '"«  cxac  iy  '  t'Tl  "'"  *'"^^*^  '•"'^' 
"f  the  water  entir.t  h,:^*,  ^' '  'J'-'^ncc.a  can  not  n,iss  i  u  d  ""  ;""^""^'  ^""^''"'-'^ 
^bffht  change  occnr  si.  triM^-^''^'  '""""''«  ^warn,  and  „'  u  ti  )  ""'"'''"  «"""'■^'■- 
tbough  a  ih^y  hoars     1        «7'''t><"Ks,  an.l  soon  scarce  v  '  ^  ^'^  thousar.ds.    a 

^"""■"■""»""'-«'-ti Ltsrf 


no 


BUl.LKTIN    (IF    THK    rMTKI*    S'lAI'i'.S    KlHIt    COMMISSION. 


those  infusoria  uppeiir  iiiid  diHaitpear  in  tin;  tMiiture  jar  about  hh  the  lower  alf^iH  do. 
The  power  of  inoveinent,  re);uhit«'d  in  the  simple  manner  above  described,  is  <;orrehited 
with  tlie  fa<;t  tlnit,  nniii^e  phuitH,  tliey  live  upon  solid  food  (baeteria)  and  are  therefore 
more  liliely  to  get  ttiis  food  if  tiiey  (;an  move  about  here  and  tlierc.  But  tiie  bacteria 
must  be  abundant  in  any  ease,  for  the  I'aramecia  have  no  power  of  searching;  for  them, 
or  of  choosing  them  rather  than  any  other  substance. 

In  future  work  it  is  hoped  to  determine  how  far  the  residts  gained  on  Parame- 
cium are  apjdicable  to  the  Protozoa  as  a  class,  as  well  as  to  extend  these  researches 
to  higher  groups,  building  upon  tlie  foundation  obtained  by  a  study  of  these  lowest 
organisms.  In  tiiis  way  it  is  hoped  that  the  laws  whicli  govern  the  movements  and 
migrations  of  animals,  the  causes  of  tiieir  appearan<-e  and  tlisappearance  at  certain 
places  or  under  given  conditions,  and  in  fact  mncli  of  their  relations  to  the  conditions 
surrounding  then)  in  the  lake,  may  in  time  be  made  out.  It  is  the  belief  of  the  writer 
that  this  is  the  most  direct  and  certain  way  of  unraveling  the  complicated  network  of 
relations  which  make  up  the  life  of  the  lake. 

In  addition  to  the  study  of  the  reactions  of  the  animals  above  suninuuized,  some 
faunistic  work  was  carried  on.  An  examination  was  made  of  the  waters  on  and  about 
South  Ilass  Island,  with  the  purpose  of  determining  the  abundance  and  general  char- 
acter of  the  Protozoan  fauna.  The  swampy  waters  of  this  region  were  found  to 
swarm  with  Protozoa  of  all  sorts,  <dlering  unlimited  supitlies  of  material  lor  work  on 
the  group  in  experimental  or  other  lines.  Unfortunately,  the  literature  was  not  at 
hand  for  complete  identification  of  all  the  species  observed,  so  that  critical  systenuitic 
work,  of  the  soi't  done  on  the  Rotatoria,  could  not  be  cairied  on  for  the  Protozoa. 
Only  those  could  be  positively  identified  that  agreed  completely  with  species  described 
in  the  standard  works  on  the  Protozoa — Leidy's  lihizopoda,  Kent's  Manual  of  the 
In/iiKorid,  Biitschli's  Protozoen,  Eyferth's  lUe  ciiifachstcn  Lt'biHH/ormtn  den  Thier-und 
PftnnzenreiehvH^  Blochniann's  lHv  mikroskopinclie  Thiencelt  dett  *'««« /<•««««•«,  Pritchard's 
Infusoria,    Khrenberg's  Die  I ii/imonNthierchen  als  rolhommein;  Organ iiimen,  etc. 

The  following  list  therefore  (lontaius  the  names  of  such  species  only  as  could  be  fully 
identified,  and  comprises  thus  but  a  fraction  of  the  Protozoan  fauna  of  the  region.  It 
is  given  in  order  to  show  something  of  the  character  of  the  abundant  Protozoan  fauna 
of  these  waters,  as  well  as  to  jioint  out  forms  that  are  of  cspe(!ial  interest  as  favorable 
objects  for  investigation.  Especial  attention  was  paid  to  forms  which  from  their  size, 
or  fnmi  the  possibility  of  securing  tlieni  in  great  abundance,  promise  to  be  particularly 
favorable  for  experimental  work. 


lioU 
folio 


a.  ▲ 

3.  Ai 

4.  Pa 
5   Co 

6.  DM 

7.  Dlfl 

8.  om 


9-  Dlffl, 

10.  Dim, 

I 

11.  Arce 

t 
12-  Centi 
13.  Bugij 


1*.  Acani 
Jill 


15.  Oikom 

nor 

16.  Anthoj 

iiaa 

17.  Oinobr 

18.  Bugleni 

wesi 
tlie  t 

19.  Buglena 

20.  Buglena 

21.  Amblyo] 

22.  Colaciut 

23.  Colaolun 

Lake 

24.  Traohelo 

25.  Tracheloi 


THE    PROTOZOA   OK    UAKK   KH.K. 


Ill 


LIST  OF  SOME  OF  THE  PRnTn7n.    r 

3-  --t,:^;i^j,  Ktrr  -F"- ■"'-      '■"-  "■' "--'» -  ■■■■  "■••  - ■• 

»»'  or  s„„„,  ..,,..,,,,,,  2 ;,°  "■""'""  "-•'  II..",.  -7  ";'  ," ""  "'""•"  '"'"".I. 

^^S=~?:£iS-"^':'- -,., 

II  Co^ac^um  steinu  Kent.    On  S^T*"""' '''"'"'  "»««  I«Ia".l. 

s  .2SSfiS£^^^^^^  


112 


lULI.KTIN    OK   TIIK    INITKI)    STATKS    KISM    (OMMIKHloN. 


26.  Traohelomoiiaa  aapera  Klir.     Hwaiiip  on  .Soiilli  IIuhn  InIuimI. 

27.  Traohelomoiicia  arinata  Klir.     [n  ai|iiittio  vi>;;otiiliiiii  from  I'.uhi  i (arbor,  l.nkn  I'.riu,  nnil  from  Kaat 

H\vaiii|i  on  South  KaNN  iNlaiul. 

28.  Phacua  lohgicaudua  Klir.    From  Kant  lliirlioi'.  I.akr  Krif,  ami  from  M\vaiii|iH  on  .Sontli  IIuhm  Inland. 

29.  Phacua  trlqueter  Klir.     Kaxt  llurlior,  l.iikit  Krio,  ami  JjiHt  .Swami),  Soiitli  HaxN  Nlauil. 

30.  Aataala  triobopbora  Kbr.     On  HliHlm  trom  KaHl  llarbnr,  Lakit  Kriu. 

31.  Bntosipbon  aulcatum  iMi.j.     In  ,jar  of  <|i'ca,vinK  Xiliuubu  liilra  from  KhhI  llarlior,  Lako  Krie. 

32.  Syiiura  uvella  Kbr.     KiMt  Sw»ni|i,  .South  ItiiMH  IhIhikI. 

33.  Chilomoiiaa  paranieoium  Klir.     Alnnnlant  in  tlHcayiiif;  watrr-jilantM  from  any  |>art  of  Lake  Grin 

or  tlif  Nwaiii|>H  on  .South  Hiihh  lHlan<l.     'I'IiIh  Ih  ono  of  IId-  Bpt'cicH  that  I'lin  alwayn  lio  |iruciiru<l 
in  iinlluiitcil  (|iiantiti<>H  at  any  tiiiio. 

34.  Moiioalgu  ateliiii  Knit.     Ou  Htciim  of  KpinUjUii  plicatiliii  from  KaHt  .'<\vuiii|i,  .South  llaNN  Ulunil. 

35.  Peridluitim  tabulatum  Khr.    In  water-hottie  collection  from  ii|i{iur  H  fi-t-t  of  f.aki^  Krie,  I  mile 

wi'Ht  of  South  IhiHM  iHlaiid;  alito  iu  aqnatio  plants  from  KaHt  Harbor,  I  ako  Krie,  and  from  the 
Hwamp.H  on  .South  ilaiM  Inlaiid. 

CILIATA. 

36.  Traohelooeica  olor  O.  K.  M.     In  rtricitlarin  from  l'ortngi>  River,  Ohio. 

37.  Colepa  birtus  Khr.     Swamp  near  liHli-hatchcry  on  .'^oiitli  lla.sH  litland. 

38.  Ampblleptiia  meleagrla  Khr.     In  ai|natic  plants  from  Ka>tt  Harbor,  Lake  Krii'. 

39.  Ampbileptus  margaritifer  Khr.     In    a<iuatii'   vegotatiuii    from    I'lit-in    May   Ilarbtir    and    Kaal 

Harbor,  l.ako  Krii«. 

40.  Llouotua  faaoiola  Khr.     In  ai|uuti<'  plantH  from  Kast  Harbor,  Kake  Kriu. 

41.  Loxopbyllum  meleagria  Khr.     On  Myniiiihjilhiiii  from  Kast  Harbor,  Lake  Krie. 

42.  Tracheliua  ovum  Khr.     On  I'triciilnria  frutn  I'ortagr  Wivcr,  Ohio. 

43.  Dileptua  anaer  <>.  F.  M.    On  ai|natic  pluntH  from  Pnt-iu  liay  Harbor.  Lake  Krie,  and  the  swatupa 

nrar  the  iUh-hutchery  on  ijoiith  Ha.ts  iHlaud. 

44.  Naaaula  oruata  Khr.     Kast  Harbor,  Lake  Krie;  Furtaf^e  Uiv()r,Ohio;  Kast  iSwamp,  South  linsH 

iHlaml. 

45.  Olauooma  aciutillaua  £hr.     Common  in  uulttireH  of  decay  iU};  lake  plants. 

46.  Colpidlum  oucuUua  Kcbraiik.     Abundant  in  iufuHiuim  of  docayin};  (JemiophyUum  from  the  bottom 

of  I'lit-iu  Hay  Harbor,  Lake  Krie. 

47.  Parairecium  caudatum  Khr.     Abiindimt  in  cultures  of  deoayinj^  lake  plantH  from  the  bottom  of 

I'ut-iu  Kay  Hurbor,  Lake  Krie.     See  pp.  1U5-11()  for  au  accouut  of  the  laws  of  the  movemeutH 
of  tbia  animal. 

48.  Urocentrum  turbo  O.  F.  M.     Abundant  in  decuyiiiK  ('eiaU)pUyllum  from  tlie  hot  tain  of  Put-iii 

Buy  Harbor,  Lake  Krie;  also  in  water  from  Kast  Swamp  on  South  Kass  iHlaiid. 

49.  CyoUdium  glaucoma  Khr.     Iiijar  of  (leeayiug  Ae^ini/(o  luiea  from  Kast  Harbor,  Lake  Krie;  many. 

50.  Spirostomum  ambiguum  Kbr.     ICoat  Harbor,  Lake  Krie,  and  LIk-  i^vvumpH  on  .'^outh  MaHS  litland. 

51.  Buraaria  truncatella  Miiller.     This  cuorniouH  infiisorian  wa.s  common  in  the  Hwanip  near  the  tish- 

hatchery  on  South  Ita-ss  l.sland. 

52.  Stentor  ceeruleus  Khr.    In  aiiuntie  vogvtatiou  from  Kast  Harbor,  Luke  Krie,  from  I'ortuge  Uiver, 

Ohio,  and  the  swamps  on  South  Hasa  Island. 

53.  Steutor  igneus  Khr.     In  KUnha  from  Kast  Harbor,  Lake  Krie. 

54.  Strombidium  turbo  C.  and  L.     In  docayiuK  SiliUa  from  Kast  Harbor,  Lake  Krie. 

55.  Halteria  graudinella  Miiller.    Many  in  L'triniltiria  from  I'ortagu  Kiver,  Ohio. 

56.  Tintiniiopsia  cyliiidrica  Daduy.     An  empty  shidi  of  what  appears  to  be  this  Bpecies,  recently 

descrilied  by  Daday,  was  taken  in  the  water-bottle  collecticm  from  the  upper  3  feet  of  Lake 
Krie,  1  mile  west  of  .South  Itass  Island. 

57.  Codonella  cratera  Leidy.     In  towings  from  I'ut-in  Itay  Harbor,  Lake  Krie.    This  seems  to  be 

the  same  as  the  Knroiieaii  CodotivUa  laciiHtrig,  but  L'-My's  name  has  the  priority. 

58.  Holoaticba  myatacea  .stein.     In  the  water'nottlu  (<.i:i>  (ion  from  the  upper  3  feet  of  Lake  Krie, 

1  mile  west  of  South  Bass  Island. 

59.  UroleptUB  muaculus  .Miiller.     Few  in  decaying    Mtei' ,  ;i  >m  Kast  Harbor,  Lake  Krie. 

60.  Oxytricha  fallax  Steiu.     Common   iu  decaying;  >'trali    i'.iUum  from  the  bottom  of  Put-in  Bay 

Harbor,  Lake  Krie.  ' 


\ 


\ 


'"■■>. 


\i 


\ 


TIIK    PIWjTOZoA    of    lake    KUIK. 


118 


61.  Trlohodina  pedloulua  Klir.    On  IHatilomuii  fioin  t<iwiii);H  in  i'lit-iii  Hiiy  llnrlior;  mi  llgHrtt  (Vnm 

Kuat  liftrbor,  I..uk<i  Krlt 

62.  VortlcelU  oouvullaria  I..     Voryalninilunton  uIkh'  rroni  I'.iutt  .Swrniip,  .'^nnlli  Hiihh  iNlaiiil. 

63.  Vortloella  ohloroatigma  Klir.     rnrininK  liirKu  ^riMMi  lutttlioit  viHiUlii  to  (lif  naktul  )•><•,  on  tlii< 

y«KOt>^llon  from  Kimt  ''.tvnin|i,  Hontli  Mamn  UIiiuiI. 

64.  Vortloella  rbnbdoatyloidea  Ki<llirott.     (.'ointnon  on  .Itttihunit  in  tiiwlnf;ii  rrtnn  l.itl<ii  Krio. 

69.  Zoothainnium  arbuaaula  Kbr.     In  aurfiti^otowiiiKH  in  I'litin  llity  Marbur,  Litko  Kritt,  utlurtiiil  tn 
lloulinK  inuttur. 

66.  Eplatylia  plioatllia  Khr.     Abmidiiut  uii  Chaia  froui  Koat  Bwump,  Kontii  I(i.>«m  InIuikI,  in  ('<ini|iiiny 

with  Megalotroeha  aUiofltiricaui. 

67.  Va^ioola  oryatalllna  Khr.    On  iii|iiiiti(!  phintH  Troni  Kiutt  Swiunp,  .Sniili  Miihh  !Nian<l.     Wlmt 

ae«<iiu  tho  hiimio  form  iH  oiton  found  iiii  t'ragiUaria  in  tuwiuga  truui  Lake  ICric;  tl'eNU8|ii!ciuK'n« 
are  ulwaya  uiiu^h  muuiler,  however.  .     t* 

SUCTORIA. 

68.  Aoineta  myataolna  Khr.    On  floating  llovroHe  material  taken  with  the  t<iw  not  in  !'ut-in  Kay 

Harbor,  Luke  Krio. 

Wbilo  the  fauiiii  iiibabitiii{(  the  plaiitH  of  tlio  bottom  and  ulioiit  thu  ttlioroM  of  this 
part  of  Lake  ICrie  is  vory  rich  in  Protozoa,  both  in  the  number  of  HpocicH  and  of 
individuals,  the  open  waters  of  tho  lake  contain  very  few.  Thouj^h  'I'i  <pei'i*'H  are 
included  in  the  list,  us  taken  from  the  waters  of  the  lake  itway  from  shore,  most  of  tlicsu 
were  present  in  very  small  numbers,  and  none  were  iibundant.  The  si>ecies  of  the 
fore<;oing  list  found  iu  the  open  waters  of  the  lake,  and  on  that  account  apparently 
to  bo  considered  limnetic,  are  the  following: 

A  mirba  prolfitn.  J  can  tkoc.iigtit  vhatoplioira. 

Aimrbti  rilloia,  IHkomonaii  termo. 

Amiiba  rariioon.  Eiitjlena  riHdis. 

Coliirinm  uleiuii. 

Colariiim  veniciilognm. 

J't-ridiiiiitm  tahu latum. 

Tintinnopgin  oylindrica, 

Vodonella  tral<:ra. 


I'amphaguH  hyaliiiuB. 
Cocklioiwdium  bilimbosum. 
IHfflui/la  curoiia. 
lHfflu(ii(i  ijtobitlosa. 
Jrcella  rulijaria. 


IfoloHlicha  iii!)ilacea. 
'JVivhodiiia  pidioaliiii. 
I'ortk'elta  rhahdoHlyluidtg. 
Xoolliamitiiim  arhiisciila. 
faginicola  crijutaUlna  (f). 
Acinela  myttaviua. 


This  list  includes  a  number  of  species  not  usually  recorded  from  open-lake  waters; 
these  are  chieHy  due  to  Professor  Keighard's  collections  with  the  water  bottle,  which 
were  made  as  follows:  A  large  corked  bottle  was  sunk  in  the  lake  to  the  desired 
depth,  the  cork  pulled  from  the  mouth,  and  the  water  allowed  to  till  ihe  bottle.  The 
water  thus  secured  was  then  filtered,  so  as  to  i)revent  the  escape  of  even  the  most 
minute  organisms.  Collections  were  thus  made  from  the  open  lake  1  mile  from  any  land, 
where  the  water  was  0  fathoms  deep.  Water  was  taken  fro.>.  the  surface  layer  not 
more  than  3  feet  below  the  surface.  Collections  so  made  contained  regularly  a  number 
of  minute  Protozoa  not  usually  accounted  limnetic,  namely: 


Aiiiitba  iiroteui. 
Amuha  eillusa, 
.Imirba  radiosa. 


Cochliopodium  bilimbosum. 
Viffliujia  globuloaa. 
Eugleiia  viridia  (unoe). 


I'eridinium  labiilatuiii. 
Tintinnopsis  vyiindrku  (only  onco). 
lloloativka  myatavea. 


The  list  is  remarkable  especially  for  the  three  species  of  Amcrha  and  one  of 
Cochliopodium.  These  rhizopods  are  very  minute,  and  would  be  lost  jy  the  usual 
methods  of  collecting.  Contiuuad  thorough  plankton  work  of  the  sort  carried  on  by 
Professor  lleighard  maf  show  that  these  are  proper  members  of  the  limnetic  fauna, 

Difflugia  (ilobuloita  was  one  of  the  very  commonest  limnetic  forn)s  in  all  sorts  of 
coUectious  from  the  open  lake. 

V.  C.  B.  1890-8 


I! 


BUM 


114 


BULLETIN   OP   THE    UNITED   STATES   PI8M   COMMISSION. 


The  passive  limnetic  forms  incladed  in  the  preceding  list  are: 


Oikomonas  tcrmo,  on  floating  lloccose  luatoriul. 
Colaciiim  steinii,  on  IHdptomus, 
Colacium  reiiieuloiium,  on  Cyclops. 
f'ortiveHa  rhabdostyloides,  on  Jnabirna, 


/oolhamnium  arbiiscula,  on  l)oatin<;  ninterinl. 
Vaginivola  cryatatlina  (f)  on  I'VaniUaria. 
Aoineta  mystavina,  on  flouting  floccosu  material. 


The  following  species  may  be  noted  as  of  special  intiTcst  because  of  their  titness 
as  objects  of  investigation  in  experimental  or  other  lines:  ^ 

Vhilomonas  parameciitm  is  a  flagellate  form  tliat  can  always  be  procured  in  unlim- 
ited numbers  by  simply  allowing  the  aquatic  plants  to  decay  in  Jars.  The  necessity 
for  large  numbers  in  carrying  on  experimental  worii  needs  no  emphasis.  The  ease  witli 
which  a  Protozoan  can  be  cultivated  in  the  laboratory  is  almost  the  most  important 
element  in  its  availability  for  investigation. 

The  species  of  Euglena,  Vhaeun,  and  Trachelomonaa  are  always  to  be  had  in  large 
numbers  from  East  Swamp,  South  Bass  Island. 

Tracheliiis  ovum,  Dileptus  anser,  and  Nasaula  or«rt/rt  are  ciliates  which  are  valuable 
for  certain  sorts  of  work  on  account  of  their  large  size.  Tlie  same  is  true  to  a  more 
pronounced  dsgree  of  Spirostomum  avibigiium,  and  especially  of  liursnria  truneatella. 
The  latter  is  an  enormous  creature  for  a  unicellular  animal,  being  a  millimeter  or  more 
in  diameter.  It  could  thus  be  handled  in  the  same  individual  way  as  many  of  the 
large  Metazoa.  This  animal  was  always  procurable  in  small  numbers  from  the  swamp 
near  the  fish-hatchery  on  South  Bass  Island.  Doubtless  a  little  experimentation  would 
discover  a  means  of  cultivating  them  in  large  numbers.  Perhaps  there  is  no  other 
Protozoan  that  would  be  so  favorable  an  object  for  an  investigation  into  the  effects  of 
localized  stimuli  and  into  the  question  of  the  localization  of  functions  in  the  Protozoan 
body  or  related  problems. 

Other  ciliates  that  could  always  be  procui^ed  in  large  numbers  are  Glaucoma 
scintillann,  Coljndium  cucullm,  Varamecium  caudaUim,  Urocentrum  turbo,  Cyclidium 
glaucovia,  and  Vorticella  convalUiria. 

For  Khizopoda,  three  species  of  Difflngia — D.  globtdom,  /).  lobosfoma,  and  D. 
corona — are  particularly  abundant  and  might  be  used  for  work  on  this  group.  Cul- 
tures properly  managed  usually  resulted  in  obtaining  large  numbers  of  various  species 
of  Amoeba. 

Species  of  Volvo.v,  Eudorina,  Fandorina,  etc.,  swarm  in  Knat  Swamp,  South  Bass 
Island;  they  are  not  included  in  the  foregoing  list.  A  study  of  the  ph^-siology  of 
these  creatures,  transitional  as  they  are  between  Protozoa  and  Metazoa,  promises 
much  of  interest. 

Dartmouth  Oolleue,  Hanover,  N.  IL,  May  25,  18!)'J. 


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